The invention is based on a magnet valve as defined hereinafter. In such a magnet valve, known from German Patent 25 03 345, the closing element is coupled to the armature of the magnet valve via a drag coupling, and the armature is embodied with its face end that plunges into the closing part as a valve element, so that this element blocks the communication between the intake line parts via the bore whenever the armature, under the influence of the restoring spring, moves or has moved the closing part into the closing position. Upon opening of the magnet valve the armature is lifted from its seat on the closing part under the influence of the magnetic force of the electromagnet, opens the bore, and only in the course of a further stroke lifts the closing part from its seat via the drag coupling, so that the force for opening the closing part, which is acted upon by both the restoring spring and the pressure prevailing upstream of the seat in the intake line, can be kept small, because a pressure equalization is effected previously via the bore.
Under certain conditions, however, it may happen with a magnet valve of this generic type that the closing part, when it is moved to the closing position, is acted upon by a pressure pulse from the pump work chamber in the course of the remaining delivery stroke of the fuel injection pump and after opening of the communication between the intake line and the pump work chamber. This pressure pulse can cause the closing part to be lifted from its seat, so that a process of refilling the pump work chamber can briefly take place via the intake line. This quantity flowing through the pump work chamber can also be brought to injection in the next delivery stroke of the pump piston, and thus the purpose of the magnet valve, which is to serve for the purpose of shutoff, is not attained. In particular, with such a defect in the control of the fuel injection pump, the internal combustion engine can race.